中国物理B ›› 2026, Vol. 35 ›› Issue (2): 27505-027505.doi: 10.1088/1674-1056/adf6a6

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Strain energy enhanced room-temperature magnetocaloric effect in Mn5Ge3

Xiaohe Liu(刘潇贺)1,2, Ping Song(宋平)1,2,†, Sen Yao(姚森)1,2, Yuhao Lei(雷雨豪)1,2, Ling Yang(杨玲)1,2, Shenxiang Du(杜深祥)1,2, Yiran Deng(邓贻然)1,2, and Defeng Guo(郭得峰)1,2   

  1. 1 Center for Extreme Deformation Research, State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004, China;
    2 Key Laboratory for Microstructural Material Physics of Hebei Province, School of Science, Yanshan University, Qinhuangdao 066004, China
  • 收稿日期:2025-05-19 修回日期:2025-07-14 接受日期:2025-08-01 发布日期:2026-02-05
  • 通讯作者: Ping Song E-mail:psong@ysu.edu.cn
  • 基金资助:
    The authors would like to thank Dr. Jie Ren for his assistance in the Monte Carlo simulations. Project supported by the National Key Research and Decelopment Program of China (Grant No. 2021YFB3500302), the National Natural Science Foundation of China (Grant Nos. U22A20116 and 52371200), and the Innovation Capability Improvement Project of Hebei Province, China (Grant No. 22567605H).

Strain energy enhanced room-temperature magnetocaloric effect in Mn5Ge3

Xiaohe Liu(刘潇贺)1,2, Ping Song(宋平)1,2,†, Sen Yao(姚森)1,2, Yuhao Lei(雷雨豪)1,2, Ling Yang(杨玲)1,2, Shenxiang Du(杜深祥)1,2, Yiran Deng(邓贻然)1,2, and Defeng Guo(郭得峰)1,2   

  1. 1 Center for Extreme Deformation Research, State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004, China;
    2 Key Laboratory for Microstructural Material Physics of Hebei Province, School of Science, Yanshan University, Qinhuangdao 066004, China
  • Received:2025-05-19 Revised:2025-07-14 Accepted:2025-08-01 Published:2026-02-05
  • Supported by:
    The authors would like to thank Dr. Jie Ren for his assistance in the Monte Carlo simulations. Project supported by the National Key Research and Decelopment Program of China (Grant No. 2021YFB3500302), the National Natural Science Foundation of China (Grant Nos. U22A20116 and 52371200), and the Innovation Capability Improvement Project of Hebei Province, China (Grant No. 22567605H).

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摘要： Large magnetic entropy change ($\Delta S_{\rm M}$) can realize a prominent heat transformation under the magnetic field and directly strengthen the efficacy of the magnetocaloric effect, which provides a pioneering environmentally friendly solid-state strategy to improve refrigeration capacities and efficiencies. The second-order magnetic transition (SOMT) materials have broader $\Delta S_{\rm M}$ peaks without thermal hysteresis, making them highly attractive in magnetic refrigeration, especially in the room temperature range. Here, we report a significant enhancement of $\Delta S_{\rm M}$ at room temperature in single-crystal Mn$_{5}$Ge$_{3}$. In this SOMT system, we realize a 60 % improvement of $-\Delta S^{\max}_{\rm M} $ from 3.5 J/kg$\cdot $K to 5.6 J/kg$\cdot $K at $T = 300$ K. This considerable enhancement of $\Delta S_{\rm M}$ is achieved by intentionally introducing strain energy through high-pressure constrained deformation. Both experimental results and Monte Carlo simulations demonstrate that the enhancement of $\Delta S_{\rm M}$ originates from the microscopic strain and lattice deformation induced by strain energy after deformation. This strain energy will reconstruct the energy landscape of this ferromagnetic system and enhance magnetization, resulting in a giant intensity of magnetocaloric responses. Our findings provide an approach to increase magnetic entropy change and may give fresh ideas for exploring advanced magnetocaloric materials.

关键词: magnetocaloric effect, magnetic entropy change, second-order magnetic transition, strain energy, deformation

Abstract: Large magnetic entropy change ($\Delta S_{\rm M}$) can realize a prominent heat transformation under the magnetic field and directly strengthen the efficacy of the magnetocaloric effect, which provides a pioneering environmentally friendly solid-state strategy to improve refrigeration capacities and efficiencies. The second-order magnetic transition (SOMT) materials have broader $\Delta S_{\rm M}$ peaks without thermal hysteresis, making them highly attractive in magnetic refrigeration, especially in the room temperature range. Here, we report a significant enhancement of $\Delta S_{\rm M}$ at room temperature in single-crystal Mn$_{5}$Ge$_{3}$. In this SOMT system, we realize a 60 % improvement of $-\Delta S^{\max}_{\rm M} $ from 3.5 J/kg$\cdot $K to 5.6 J/kg$\cdot $K at $T = 300$ K. This considerable enhancement of $\Delta S_{\rm M}$ is achieved by intentionally introducing strain energy through high-pressure constrained deformation. Both experimental results and Monte Carlo simulations demonstrate that the enhancement of $\Delta S_{\rm M}$ originates from the microscopic strain and lattice deformation induced by strain energy after deformation. This strain energy will reconstruct the energy landscape of this ferromagnetic system and enhance magnetization, resulting in a giant intensity of magnetocaloric responses. Our findings provide an approach to increase magnetic entropy change and may give fresh ideas for exploring advanced magnetocaloric materials.

Key words: magnetocaloric effect, magnetic entropy change, second-order magnetic transition, strain energy, deformation

中图分类号:  (Magnetocaloric effect, magnetic cooling)

  • 75.30.Sg
62.20.F- (Deformation and plasticity) 75.47.Np (Metals and alloys)